1824.] On the Chemical Composition of Red Silver Ore. 29 



Article V. 



New Investigation of the Chemical Composition of Red Silver 

 Ore* By P. A. v. Bonsdorff. 



In consequence of the analysis of red silver ore by Klaproth 

 and Vauquelin, this mineral has been considered as a compound 

 of sulphuret of silver, sulphuret of antimony, and oxide of anti- 

 mony. Klaproth's last analysis of this mineral from Andreas- 

 berg (Beitrage, v. 197) makes its constituents as follows : 



Silver 60 



Antimony 19 



Sulphur 17 



Oxygen 4 



100 



But both in this analysis, and in the others made upon the 

 same mineral, although the quantities of constituents obtained 

 were unequal, no positive proof was obtained of the presence of 

 oxygen, or of oxide of antimony. It was merely concluded that 

 the great loss sustained during the analysis was owing to the 

 presence of oxygen. In this way Vauquelin reckoned the whole 

 loss, which was about 12 per cent, as oxygen. And Klaproth, 

 for the same reason, reckoned 4 or 5 per cent, of oxygen in his 

 different analyses. But as the result of these analyses do not 

 agree with any atomic proportions ; and as both the existence 

 and amount of the oxygen still depend upon imperfect and 

 uncertain evidence, I was in hopes that a new analysis might 

 not be destitute of all interest. In Prof. Berzelius's laboratory, 

 I lately enjoyed a fortunate opportunity of undertaking the ana- 

 lysis of the dark red silver ore from Andreasberg ; and I propose 

 in this paper to give an account of the analytical experiments 

 which I undertook, and of the result of them. 



The first attempt was to extract the supposed oxide of anti- 

 mony from the mineral by means of dilute muriatic acid. Picked 

 specimens of the ore were reduced to the finest possible powdeiyf - 

 and digested with muriatic acid, rendered so weak as not to be 

 able to decompose sulphuret of antimony. This degree of dilu- 

 tion was determined by means of a paper dipped in acetate of 

 lead ; but it was found that the acid when thus diluted would 

 dissolve nothing whatever from the mineral. 



» Translated from the Kongl. Vetenskaps Acailcmiens Handlingar for 1821, p. 

 338. 



t The pulverisation of this mineral is attended with considerable difficulty, because 

 the parte of it become at last scaly, alter which it is far from easy to reduce them to a 

 liner powder, even under water. 



